The 5.45 x 39 mm Russian M74 53 gr FMJ (7N6) boat-tailed bullet has a copper-plated steel jacket surrounding an unhardened steel core and a small 5 mm long empty air-space under the bullet nose. Its typical muzzle velocity is 3066 f/s. In contrast to the older 7.62 x 39 mm Russian M43 Type PS which it replaced, the 5.45 x 39 mm M74 53 gr FMJ commonly exhibits very early yaw in tissue, at approximately 2.75", but no deformation or fragmentation. In both uncomplicated extremity and torso wounds, the very early yaw allows the bullet to travel sideways through the body, increasing permanent tissue destruction and temporary cavitation effects. A small punctate entrance wound is present and the exit wound may be punctate, oblong, or stellate depending on the bullet yaw angle on exit. Penetration is approximately 21.6. 5.45 x 39 mm M74 is a lot like an early yawing 5.56 mm bullet that does not fragment--for example M995, but without the AP capability. Good 5.56 mm loads, like the fragmenting Hornady 75 gr or Nosler 77 gr OTMs, barrier blind loads like the 55/62 gr Federal Tactical TBBC's or Nosler 60 gr Partition JSP, not to mention the new ATK/Crane Mk318 Mod0 OTM SOST load are all superior to 5.45 x 39 mm. I am unaware of any good terminal ballistic testing on commercial 5.45 x 39 mm loads.
In discussing 7.62x39 mm FMJ, the question is always which one, as their characteristics are highly variable.
In fact, there is a bit of a controversy brewing in some of the AARs coming in from OCONUS on the effectiveness of 7.62 x 39 mm ammunition. Initially, this appears somewhat strange, as there may be more forensic data available regarding wounds caused by the Russian 7.62 x 39 mm FMJ than for any other rifle cartridge. The original 7.62 x 39 mm Russian M43 Type PS 120.5 gr FMJ boat-tail bullet has a copper-plated steel jacket covering a large steel core and a typical muzzle velocity of 2340 f/s. In tissue, it typically travels approximately 9.8 to 10.6" point forward before beginning significant yaw. Most uncomplicated wounds of the torso and extremities have small punctate entrance and exit wounds and exhibit minimal internal tissue disruption since the bullet does not deform or fragment and usually exits before yaw occurs. Total penetration is around 29.1. WDMET (Wound Data and Munitions Effectiveness Team) collected extensive forensic data on over 700 7.62 x 39 mm gunshot wounds during the Viet Nam war. The predominant feature of this cartridge is the MINIMAL amount of damage it produces in soft tissue wounds, on par with FMJ handgun wounds such as those produced by 9 mm M882 ball. We also have extensive law enforcement data, as this cartridge has been used extensively in illicit activity. For example, in the 17 January 1988 Stockton school shooting, 30 of 35 kids who were shot lived. Of the five that died, all were shot in critical structure--head, heart, spine, aorta and none had damage to any organ not directly hit by a bullet.
However, not all 7.62 x 39 mm FMJ bullets are of the original steel core construction. Significantly increased tissue damage is produced by the early yaw seen with several 7.62 x 39 mm FMJ lead core bullets, including:
-- Yugoslavian M67 124 gr FMJ, flat based, copper-jacketed, lead core bullet which travels only 3.5" in tissue before yawing
-- Chinese (PRC) 7.62 x 39 mm 123 gr FMJ, copper-jacketed, lead core bullets which begin their yaw after only 2 to 2.5" of travel in tissue.
-- Czech and several types of Western commercially produced lead core 7.62 x 39 mm FMJ yaw within the first 2 to 3 inches of travel in tissue.
In both uncomplicated extremity and torso wounds, the very early yaw of these lead core 7.62 x 39 mm FMJ bullets allow the projectiles to travel sideways through the body, substantially increasing permanent tissue destruction and temporary cavitation effects compared to the standard 7.62 x 39 mm Russian M43 Type PS 120.5 gr FMJ. These early yawing lead core 7.62 x 39 mm FMJ bullets cause wounds very similar to the 5.45 x 39 mm Russian M74 53 gr FMJ bullets, however, the larger size of the 7.62 x 39 mm bullets results in a bigger permanent cavity compared to 5.45 x 39 mm bullets.
The differences in terminal effects seen in recent combat with 7.62 x 39 mm FMJ wounds can likely be explained by the different terminal effects caused by the various types of FMJ construction.
When one moves to a expanding/fragmenting design in 7.62 x 39 mm, terminal performance is significantly enhanced. The best 7.62 x 39 mm loads we have tested to date are the Hornady 123 gr VMAX, Winchester 123 gr JSP (X76239) and the Lapua 125 gr JSP. Out of a 16 barrel they perform somewhat like lightweight .30-30 loads:
Horn 123 gr SST (improperly labeled VMAX)
Bare Gelatin: vel=2242 f/s, pen=15.6", RD=.58", RL=.32", RW=99.6 gr
Unable to recover any auto windshield shots, as all projectiles exited at an angle out of the gel block after 12-13'' pen.
Lap 125 gr JSP
Bare Gelatin: vel=2316 f/s, pen=17.3, RD=.62, RL=.43, RW=122.6 gr
Car Windshield: vel=2323 f/s, pen=14.8, RD=.60, RL=.40, RW=110.6 gr
Win 123 gr JSP
Bare Gel: vel=2253 f/s, pen=14.4, rd=0.56, rw=90.1gr
Pretty much the same results when going through car windshields.
Of note, most of the cheap Russian JHP/JSP ammunition offers poor terminal performance. The one that seems to work is the 7.62x39mm Saspan 124 gr JHP (Ulyanovsk Machinery Plant; 8M3 bullet); from a 16 AKMS the data is:
BG: vel=2297 f/s, pen=15.0, Max TC=10cm@18cm, RD=0.63, RW=100.5gr"
Because of the larger permanent cavity and greater bullet mass, the 7.62 x 39 mm JSPs offer somewhat better performance than the .223 bonded JSPs, like the Trophy Bonded Bearclaw use in the Federal Tactical loads. These 7.62 x 39 mm JSP loads are a good choice for use against car windows and should also be outstanding for hunting deer and other similar size game.
In a CQB setting, the expanding 7.62 x 39 mm bullets tend to retain their mass and are very likely to exit target; the 6.8 mm OTM and PT will upset and are unlikely to exit the torso. Both will work, although I would prefer the 6.8 mm for this setting. While 7.62 x 39 mm has the potential to offer good terminal performance when using well engineered ammunition, like the 123 gr Hornady SST, and it offers better intermediate barrier penetration than 5.56 mm, the 6.8 mm is generally more accurate, flatter shooting, longer ranged, and demonstrates better terminal performance than 7.62 x 39 mm. The 6.8 mm is more versatile and effective than 5.45 x 39 mm, 5.56 mm and 7.62 x 39 mm. The new .300 BLK performs similarly to the best 7.62 x 39 mm loads, but functions more reliable in the AR15 FOW; .300 BLK also can offer a bit better accuracy at longer ranges.
The 7.62 x 54 mm Russian M1898/1908 Type L 148 gr FMJ hollow based bullet has a copper-plated steel jacket covering a lead core and a typical muzzle velocity of just under 2800 f/s. These bullets generally travel point forward for 6" or so, causing minimal tissue damage. The bullets then yaw, turning 180 degrees and continuing base forward for a total penetration in excess of 20 without further yaw. In uncomplicated extremity wounds, the bullets will frequently exit before yawing, causing little tissue disruption and small punctate entrance and exit wounds. If the bullets yaw while still traveling in tissue, in the thick torso for example, the permanent and temporary cavity are increased while the bullets travels sideways, resulting in a greater amount of crushed tissue and extensive damage to inelastic tissue. Exit wounds may be punctate, oblong, or stellate depending on the yaw angle of the bullets on exit. The wounds from the 7.62 x 54 mm are nearly identical to similar size U.S. bullets, including: the original pre-WWI spitzer .30-06 FMJ loading, pre-WWII .30-06 M1 ball, WWII .30-06 M2 ball, .30-06 M72 Match, 7.62 x 51 mm M59 FMJ, current 7.62 x 51 mm M80 ball load, and 7.62 x 51 mm M118 SB (Match). All of this ball ammo has nearly identical the terminal performance with a relatively long neck and single yaw cycle. The 7.62 x 54 mm Type L FMJ is still in wide use with PK machine guns and may be found being used in obsolete, but rugged M1891/30 Mosin-Nagant rifles.
The Czech 7.62 x 54 mm LPS 148 gr FMJ has a similar wound profile to the 7.62 x 54 mm Russian M1898/1908 Type L 148 gr FMJ, except the bullet begins to yaw much earlier, at around 2.4 to 3 of travel through tissue. As a result, wound effects are signficantly increased compared to the Type L bullet; the very early yaw initiation increases permanent tissue destruction and temporary cavitation effects compared to the standard 7.62 x 54 mm Russian FMJ. A small punctate entrance wound is present and the exit wound may be punctate, oblong, or stellate depending on the bullet yaw angle on exit. Penetration of these bullets is in excess of 20.
The specialized 7.62 x 54 mm 200 gr FMJ sniper ammo for the Dragunov SVD imported into the U.S. by Wolff is an exception to the above wounding effects, as this ammo acts more like M852/M118LR. These Russian sniper bullets typically have a muzzle velocity approaching 2600 f/s and travel approximately 5" point forward before beginning to deform, yaw, flatten, and fragment. Approximately 60% of the bullet weight is lost to the multiple fragments which spread radially outward from the primary bullet path. The multiply perforated tissue is unable to resist the stretch induced by temporary cavitation and extensive tissue destruction occurs. Uncomplicated extremity and torso wounds would likely exhibit a small punctate entrance wound. If the bullet exits before deforming or yawing, minimal tissue disruption will occur and a small punctate exit wound will be present. After the bullet yaws, deforms, and fragments, tissue destruction is greatly increased; torso wounds are often fatal and exit wounds may exhibit large tissue defects. If the bullets fail to fragment, then they act just like the FMJ's described above.
Of course, there are also Russian AP and API loads...